1. Field of the Invention
The present invention relates generally to a data recording and/or retrieving memory system together with a method and apparatus for generating a data recording area defining signal. More specifically, the present invention relates to a method and apparatus which generates a sector control signal in order to define an appointed data recording area or sector on a data storing medium whereby information is recorded by means of beam irradiation.
2. Description of the Prior Art
A data recording and/or retrieving memory system with high bit packing density data storing or storage medium is known as, for example, a magnetic disc, a magnetooptical memory or a laser disc system. On this data storing medium the information to be stored is recorded in the defined area in a sector, i.e., the multitude division of a track on the data storing medium. A pre-formatted (previously formatted) area (PFA) in a sector contains an index area and the indexes of the address for an adjacent information area, i.e., a data-write-area (DWA) in which data is to be recorded. In order to record the data in the suitable information area, the index signal and the address information are derived from the index pattern in the index area and the following indexes on the said pre-formatted area (PFA).
Thus, in prior art, the information is recorded on the said address in the said data-write-area (DWA) by using the address information derived from the the pre-formatted area (PFA). This prior art is obviously in a less than satisfactory situation when recording high density information and has serious drawbacks of recording on the wrong area or destroying the information stored in the adjacent sector when there is a defect on the data storing medium especially on the pre-formatted area.